Why smoked turkey legs in Japan?

I’ve been looking for British Xmas food in Tokyo for my new blog, and most international supermarkets that cater mainly to Japanese people such as Seijo Ishii and Kinokuniya have smoked turkey legs that look like a kind of ham rather than any uncooked turkey. 82 Ale House also had it on the menu last night.

This could well be just my overactive imagination, but I can picture it being something imported for the Occupation troops and then picked up by the locals, as was the case with spam. Then again, Japanese bacon is always cooked and more like ham too, so maybe it is just the influence of the big ham companies like Nippon Ham and Nissin. Why the ham companies are so big would be another good JapanExplained kind of question, of course…